- Radio Free Europe/Radio Liberty Research Institute (RFE/RL Research Institute)10,630
- Dyulgerov, Georgi2
- Chary, Frederick B.1
- Cohen, Francis1
- Constant, Stephen1
- Crampton, R. J.1
- Dochev, Ivan1
- Evans, Stanley G.1
- Jasienica, Paweł1
- Laber, Jeri1
- Leningradskaia Studiia Dokumentalnykh Filmov (LSDF)1
- Magyar Film Intézet1
- Radev, Simeon1
- Sklar, Morton H.1
- Slavov, Atanas1
- Traikova, Eldora1
- Zang, Ted1
- Şimşir, Bilâl N.1